Chitose Kaginoji is a wealthy 14-year-old with blonde hair, amber eyes, and a taste for elegant attire, typically a red dress paired with a black skirt and a red hair ribbon. Her constant companions are maids Aurora and Charlotte. Chitose fervently regards Tsukasa Yuzaki as her sister, using the formal "Nee-sama," despite no blood relation. This devotion stems from Tsukasa saving her from a childhood cliff fall, an event that made Chitose dedicate her life to Tsukasa's well-being. She displays a tsundere personality, shifting between assertiveness and whining. Highly gullible, she readily accepts Tsukasa's statements without question. Chitose contrasts with her mother, renowned Japanese-style painter Kagi no Tera Shiori, being far more boisterous and expressive. Rumors suggest she might be a quarter American through her grandfather. Chitose's initial fierce opposition to Tsukasa's marriage to Nasa Yuzaki drives her actions. She visits their apartment, criticizing its modesty and trying to retrieve Tsukasa. When thwarted, she orchestrates schemes to sabotage the relationship, including kidnapping Nasa and deploying her maids to create scandals. These plans often fail due to Charlotte's overenthusiasm or Chitose's own indecisiveness. During Nasa and Tsukasa's Kyoto trip, Chitose follows, aiming to exploit marital rifts. She confronts Tsukasa about her mysterious past and non-human nature, but interruptions force her retreat. Later, Nasa invites her for a private talk where she tests his worthiness by pretending to be his lover. Though skeptical about his ignorance of Tsukasa's history, she becomes impressed by his organizational skills and genuine kindness. Observing Nasa's sincerity and the couple's unshakeable bond gradually softens Chitose's stance. While initially declaring herself Tsukasa's future partner, she eventually ceases active interference, visiting occasionally to check on their well-being. Her family connections include being Tokiko Tsukuyomi's granddaughter and sharing a grand aunt with Tsukasa. Chitose is academically successful and popular at school, though she sometimes skips classes to pursue Tsukasa. She interacts with Aya Arisugawa in a tsundere manner.